Telephone-exchange system



S t. z, 1924.- 1,506,901

J. A. HAL L TELEPHONE EXCHANGE SYSTEM Filed April 17. 1920 Patented Sept. 2, 1924.

UNITED STATES PATENT OFFICE.

JOHN A. HALL, or BAYSIDE, NEW YORK, ASSIGNOB, '110 wnsrnrm ntncrarc con IPANY, INCORPORATED, OF NEW YORK, N; Y.,

A conrona'rioit or New YORK.

TELEPHO'N E-EXCHAN GE SYSTEM.

Application filed' April 17, 1920. Serial No. 374,587.

To all? whom z'tmay concern:

Be it known that I, JOHN ALDEN HALL, a citizen of the United States, residing at Bayside, in the county of Queens, State of New York, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the followingis a full, clear, concise, and exact description.

This invention relates to telephone systems and particularly to means for automatically connecting a calling line to an idle trunk.

The object of the invention is to provide a simple and efficient means, free from mechanical contrivances for preselecting and allotting idle trunks leading from a nonnumerical switching apparatus of the type known as the cross bar switch.

In accordance with this object, a starting circuit is provided which will be made effective by the usual line relays associated with the calling lines. The actuation of a line relay will change the condition of the starting circuit so as to cause the movement ofthe trunk bar associated with the first idle trunk. This movement will result in the closing of a return starting circuit which,

through the control exercised over it by the line relay, will cause the energization of the line bar associated with the calling line. The movement of the line bar causes the engagement of the actuated trunk and line bars, whereupon the line is extended to the idle trunk, the idle trunk is marked as busy and the trunk bar is released, now being held only by the continued actuation of the line bar. I The line bar magnet acts as a cutoff relay to disconnect the line relay from the line and the trunk bar magnet together with an auxiliary relay act to extend the starting wire to the next idle trunk.

The drawing is a diagrammatical repre sentation of a-means for carrying out the present invention.

1 and 2 represent so-called line bars. Each of these has a plurality of sets of multiple contactmembersifl towhich the tip, ring and sleeve conductors of the telephone lines are connected. The line bar 1 is associated with a substation 4 and the line bar 2 is associated with a substation 5. Bar 1 is rotatably mounted in the frame of the switch by meansof pivots 6 and 7 and it is-normally moved toward the right by means of a coiled spring 8 wound around the pivot 6. The" bers 17 which are connected to trunk linessuch as18. By means of a lever arm 19, the trunk bar 15 may be rotated by the move ment of an armature 20 of a trunk bar magnet 21.

Such a cross-bar switch operates in the, following manner: First, the trunk bar 15 is rotated in a clockwise direction. Thereupon, the line bar is rotated in a counter-clock wise direction until the multiple contact members 3 come into engagement with the multiple contact members 17. The trunk bar is then released and the contact members 17 which have made engagement with one set of contact members 3 are stressed into the position as indicated in the set shown directly above the trunk bar magnet 22. The remaining sets of multiple contact members 17, individual to trunk bar 15 resume their normal position where they will notbe engaged by any other multiple sets of contact members 3.

The manner in which the arrangement shown operates is as follows: It will be assumed that substation 5 has initiated acall and is connected through the line bar 2 and the trunk bar 15 to a trunk connected to conductors 23. In this case, as will be hereinafter more full pointed out, a relay 21 associated with t e the substation 4 initiates a'call, a circuit will be completed from battery, the righthand winding of relay 25, contact springs 26, through the loop at the substation 4.-

I 0 contact spring 27, the left-hand winding of relay 25 to ground. Relay 25 attracts A cam arrangement 11 cooperating trunk bar magnet 21 will be in its energized condition. It now' 30, the right-hand armature and alternate contact of relay 24,the contacts 31 and 40 controlled by the trunk bar magnet 22, the right hand armature and back contact of relay 33,,thewinding of trunk bar magnet 22, the winding of relay 33 to battery and ground. Both magnet 22 and relay 33 are energized in this circuit. Magnet 22,

7 through its armature, rotates thetrunl r bar 14 and relay 33 quiclrlyv pulls up'its lefthand armature, and slowly pulls its right-- hand armature due to the influence ofia spring 34;. The energizing circuit for magupon the contact members 3 and 17 shown in the upper left-hand corner of the figure come into engagement. It should be noted at this point, that the windings of magnet 9 are so designed that the energization of ""the'right-hand windings will cause the attraction of both the right-hand and lefthand: armatures and that the subsequent '-energization of the left-hand windings will hold both of these armatures attracted. If,

whowever,'theleft-hand windings are energized first, only the left-hand armature will be attracted since it doesnot work against as heavy a spring as the right-hand arma I ture.

' becomes deenergized.

.on thethird conductor of trunk'18 is also extended through conductor 41' to the leftactuated position.

The telephone line from substation 4: is now extended through the contact members 3 and 17 to the trunk 18 whereupon the loop at the substation closes a circuit for the energization of relay 38. Relay 38 attracts its I v armature and closes a circuit for the ener gization of slow-releasing relay-39 which, in turn, through its right-hand armature, places a ground on thethird conductor of trunk '18. This ground extends through the contact and left-hand armatme of relay 33, the winding of relay 33 to battery and ground. At the same time, it

.shunts the winding of. magnet. 22 so that relay 33 remains energized and magnet :22 The-ground placed hand windings of magnet'9. to battery and ground; whereby the magnet9 is held in its armature, magnet 9 actuates the contacts 26 and 27 to cut oil the relay 25 from thelineof substation 4. Thereup'on the ground Through its left-hand is removed from the conductor 28 and the right-hand windings of magnet 9 are opened.

All of this operation has taken thesmallest fractionof a second and it will be assumed that shortly after, the right hand armature of relay 33 moves to its attracted position, whereupon the conductor 28 is extended through the contacts 29 and 30, the

right-hand armature, of relay 24:, contacts 31 and 4L0, the right-hand armature and con :tact of relay 33 and thence to the winding of the next in turn trunk bar magnet.

It should be noted that. as soon as the trunk bar magnet 22 becomes energized and before the right-hand armature of relay 33 moves to its attracted position, the starting conductor 28 is extended to the winding of magnet 22 throughthe contacts 31 and 10, the right-hand armature. and back contact of relay 33, the winding ofma-gnet 22 in place of the circuit heretoforedescribed.

Since further extension of the call over thetrunk 18 forms no part of the present invention, it will notbe further described.

Upon the termination of the conversation,

the subscriber at substation 4r replaces his receiver on its hook and thereby deenergizes relay 38 resulting in the removal of ground from the third conductor whereby relay 33 and magnet 9 are deenergized and retract their armatures and the apparatus returns to. its normal position.

On a call incoming to the substation 4, I

the third conductor 41 is grounded in a wellknown manner and the line bar magnet 9 attracts only its leftehand armature to cut Oil? the relay 25 from the influence of the line. i

What is claimed is: y 1. .In a switching mechanism, line bars each comprising a'movable structure carry-.

ing a: plurality of sets of multiple contactf members, trunk bars each comprising a movable structure carrying a plurality ofisets.

of multiple contact members, said line bars and said trunk bars being constructed and arranged to cooperate whereby connections may be extended from any line bar to anytrunk bar, .magnets .for operating said line bars, magnets for operating said trunk bars, a line relay associated with each line bar magnet, .an auxiliary relay associated with each trunk bar magnet, acircuit controlled by said line relays normally extending through the first of said trunk bar magnets, and means controlled by said auxiliary relay associated with saidtrunk bar magnet for extending said circuitto the next trunk bar.

magnet. is

2 1A plurality of .magnets,..an auxiliaryrelay. associated with each of said magnets, a second plurality of. magnets; an auxiliary relayassociated with :each' of said second magnets, a circuit controlled by said first.

relays extending to the first in order of said second magnets, means controlled by said auxiliary relay associated with said first in order of said second magnets for extending said circuit to a second in order of said second magnets, a circuit controlled by said second magnets and said first relays for controlling said first magnets, and means jointly controlled by said first and said second magnets for controlling said first magnets.

3. A plurality of magnets, a relay associated with each of said magnets, a second plurality of magnets, a relay associated with each of said second magnets, a circuit controlled by said first relays extending to a first in order of said second magnets, means controlled by said relay associated with said first in order of said second magnets for extending said circuit to a second in order of said second magnets, a circuit controlled by said second magnets and said first relays for controlling said first magnets, means jointly controlled by said first magnets and said second magnets for controlling said first magnets and means controlled by said first magnets for controlling both said circuits.

4. A magnet, a relay associated with said magnet, a second magnet, a relay associated with said second magnet, a circuit controlled by said first relay for controlling said second magnet, a circuit controlled by said second magnet and said first relay for controlling said first magnet, means jointly controlled by said first and second magnets for controlling said second relay, and means controlled by said second relay for further controlling said first circuit.

5. In a telephone system, a cross bar switch comprising a plurality of line bar magnets, an auxiliary relay associated with each of said magnets, a plurality of trunk bar magnets, an auxiliary relay associated with each of said trunk bar magnets, a circuit directly controlled by said first auxiliary relays for controlling the first in order of said trunk bar magnets, and means controlled by the first in order of said second auxiliary relays for extending control of said circuit to the next in order of said trunk bar magnets.

6. In a telephone system, a cross bar switch comprising a plurality of line bar magnets, an auxiliary relay associated with each of said magnets, a plurality of trunk bar magnets, a circuit controlledby said auxiliary relays for controlling said trunk bar magnets, and a circuit controlled by said trunk bar magnets for controlling said line bar magnets.

In witness whereof, I hereunto subscribe my name this 16th day of April, A. D. 1920.

JOHN A. HALL. 

